1. Field of the Invention
The present invention relates to reproducing apparatuses and reproducing methods for reproducing information from recording medium on which information is recorded using run-length limited coding.
2. Description of the Related Art
Data recording techniques using optical discs such as CDs (compact discs) and DVDs (digital versatile discs) as recording media for recording/reproducing digital data are known.
Optical discs include, for example, reproduction-only optical discs, such as CDs, CD-ROMs (CD read-only memories), and DVD-ROMs (DVD read-only memories), on which information is recorded as embossed pits, and recordable optical discs, such as CD-Rs (CD recordables), CD-RWs (CD rewritables), DVD-R (DVD recordables), DVD-RWs (DVD rewritables), DVD+RWs (DVD plus rewritables), and DVD-RAMs (DVD random access memories) on which user data can be recorded. Data can be recorded on such recordable optical discs by employing recording techniques such as magneto-optical recording, phase-change recording, and dye-film change recording. Dye-film change recording is also called write-once recording and is preferred for a data storage application, since it permits recording of data only one time and does not permit rewriting over recorded data. In magneto-optical recording and phase-change recording, on the other hand, rewriting of data is permitted. Thus, these recording techniques are used for various applications such as recording of content data of music, movies, games, and application programs.
In recent years, a high-density optical disc called Blu-ray Disc® has been developed with a view to significantly increasing recording capacity.
These optical discs store information in the form of embossed pits, dye-change marks, phase change marks, or the like (hereinafter collectively referred to as “marks”). In many cases, marks on a disc are formed on the basis of a signal obtained by modulating original data into run-length limited codes.